This invention relates to a hydraulic exerciser and particularly concerns an exerciser which can provide resistance to a pulling force.
There are various kinds of hydraulic exercisers for the training of the human body in which hydraulic power is utilized to provide a resistance opposite to the pulling force exerted by the user. When the user repeatedly tries to overcome the resistance, the energy of his muscle is consumed and as a result his muscles become stronger.
A hydraulic mechanism used in conventional exercisers is shown in FIG. 1, which comprises a cylinder 10 having a cap 30 attached to the upper end thereof, a bearing 20 disposed adjacent to the junction of the cap 30 and the cylinder 10, a piston rod 40 slidably mounted within the cylinder 10 and on the end of rod 40 a handle (not shown) is connected. The cylinder 10 includes an inner tube 101, and working fluid is received in the space between the piston rod 40 and the inner tube 101. When the piston rod 40 is pulled, the fluid such as oil, will flow through the clearance 201 between the piston rod 40 and the bearing 20 to the inner space of the cap 30, from where the oil flows to the outer tube 102 through the hole 202. Since the hole 202 has a small diameter, a large resistance is produced when the oil passes therethrough, and this resistance acts against the pulling action of the piston rod 40, when the user tries to overcome such resistance, thus affecting physical training.
However, the conventional device is unsatisfactory because the resistance provided by the oil cannot be adjusted, therefore, a single device may not be suitable for users of different strengths, physical conditions, ages, sexes, etc.